The present invention relates to a hydroplaning detecting system for detecting a hydroplaning condition of a wheeled vehicle, and a vehicle traction control system which can control a traction of a wheeled vehicle adequately even if a hydroplaning condition is present.
Japanese Patent Provisional Publication No. 64-60463 shows a hydroplaning detecting system which produces a signal indicative of presence of a hydroplaning condition when the vehicle speed is in a high speed range and a deceleration of an undriven wheel speed sensed by a wheel speed sensor is great. In the hydroplaning condition, the wheels behave as if there was a drive wheel slip and the traction control should be initiated. However, this is not a genuine drive slip but a pseudo drive slip. Therefore, this conventional system inhibits the brake control in the hydroplaning condition.